Implantation Bleeding? 7 weeks postpartum

I'm 7 weeks postpartum and started my period on the 26th of November. It finished on the 1st if December and my partner and I have had unprotected sex on the 2nd, 9th and 10th. Today, after no bleeding, felt minor cramps and when I went to the toilet there was blood on my pad (pic below) and when wiping. Then some light spotting.

What do people think? Is this implantation bleeding? Something else? I can't figure out if it's too heavy or not.

Thanks in advance!